Tufted scatter rugs with double coated skid-resistant backing and method of preparing same



w. J. MOHR 3,227,574 TUFTED SCATTER RUGS WITH DOUBLE COATED SKID-RESISTANT BACKING AND METHOD OF PREPARING SAME Jan. 4, 1966 Filed May 20, 1965 llll. ulr lll I llll INVENTOR FIG. 5

WILFRED J. MOHR ATTORNEY TUFTED SCATTER RUGS WITH DOUBLE COATED SKID-RESISTANT BACKING AND METHOD OF PREPARING SAME Wilfred J. Mohr, Textile Rubber and Chemical Company, Inc., Rte. 1, Dalton, Ga. Filed May 20, 1965, Ser. No. 457,456 5 Claims. (Cl. 117--45) The present invention relates to improved, inexpensive light-weight launderable tufted carpets and rugs having enhanced skid-resistant characteristics. In particular, the invention concerns tufted scatter rugs having a first continous back coating to provide stiffness and body to the rug and a second back coating applied only to the bottom stitches of the tufts to provide excellent skid-resistant properties. This application is a continuation-in-part of application Serial No. 212,323, filed July 25, 1962, now abandoned.

Non-woven or tufted scatter rugs and carpets have been coated in the past with a variety of back coatings to anchor the tufts and prevent unraveling of the backing fabric. These light-weight, inexpensive tufted rugs have been fabricated by stitching tufts of fabric on a base. The tufts usually comprise open and closed looped natural or synthetic organic fibrous materials, like cotton, polyester, rayon, nylon, cellulosic fibers, polypropylene and the like. These light-weight and inexpensive rugs and carpets have been designed to be cleaned and laundered in a typical home washing machine and drier.

Unlike the heavy, more expensive woven rugs, such as the oriental-type rug, these scatter rugs require an inexpensive back coating which will provide good stiffness, bulk and body to the rug, and yet permit the rug to withstand normal dyeing and laundering processes. Elastomeric back coating compositions when dried and cured provide sufficient bulk and stiffness to cause the rug or carpet to lie flat on the floor. A typical back-coating latex composition would comprise a high styrene-content SBR latex, highly loaded with inert filler material such as clay. The use of large amounts of filler is necessary inorder to maintain an inexpensive back-coating composition, while providing bulk and weight to the rug. However, large amounts of fillers rapidly degrade any inherent anti-skid characteristics of the elastomer used in the composition. Typically highly loaded elastomeric compositions frequently reduce the coeflicient of friction between the scatter rug and a smooth varnished wooden floor to the dangerous level before dyeing or further processing of 0.5 or less. Of course, the employment of a single high-content elastomer latex coating to provide anti-skid characteristics and desired stiffness characteristics would be prohibitorily expensive for this use. Therefore, present back-coating compositions represent a compromise between desired skid characteristics and the properties of weight, tuft lock, stiffness, abrasion resistance, laundering ability and other qualities. The problem of effective skid-resistance is further aggravated with lightweight inexpensive tufted scatter rugs having protruded back stitches, since these stitches reduce the effective surface fioor contact area and therefore have an enhanced stepping on this type of a rug.

United States Patent 0 'ice It is therefore an object of this invention to provide a light-weight, inexpensive, non-woven or tufted scatter rug and carpet having excellent anti-skid properties, together with good stiffness and body, abrasion resistance and the ability to withstand normal dyeing and laundering processing, all at a low cost.

It has now been discovered that inexpensive tufted scatter rugs and carpets having exceptional anti-skid qualities together with good weight, bulk, stiffness, abrasion resistance and laundering properties can be fabricated by back-coating the rug in a particular manner in two steps with two distinctive coating compositions. The first composition comprises an inexpensive, highly loaded latex composition coated on the back surface at a relatively high coating weight. This first coating on drying and curing produces the desired qualities of bulk and weight. The second coating composition is formulated to provide good skid-resistant properties, e.g., to have a high elastomer content, and is coated solely on all or substantially all of the top portions of the raised back stitches. The second coating comprises a more expensive lightly or non-loaded elastomeric latex composition coated over the first partially dry coating or directly onto the raised back stitches at a relatively low inexpensive coating weight. The first coating is a substantially continuous coating over the back surface of the scatter rug, While the second coating is a discontinuous coating only on the back stitches, but substantially over all the raised back stitches of the rug to promote exceptional skid resistance. This twostep coating method and compositions permits the desirable properties constituted by each particular composition to be retained without mutual degradation and without compromising the desirable properties of each composition. Further, not only does this two-step coating method provide in combination unexpected benefits, but these benefits are derived in an inexpensive manner which enables them to be incorporated into rugs of the character described. Heavy expensive woven rugs do not require a first coating composition to cause the rug to lie flat, While further, these rugs are normally of sufficient weight so that good skid resistance is inherent and of sufiiciently high value that the cost of any back coating is not a substantial economic factor.

With tufted carpets or fabrics having open or closed loop fabric on the forward face, the back surface may comprise random or uniformly arranged raised fibrous formations of protruding back stitching. The application of the more expensive solid or foamed elastomer second coating to the upper parts of all the raised stitches in the back floor contact area accomplishes excellent antiskid properties at a substantially reduced cost without reducing or compromising the necessary bulk, weight, stiffness, or abrasion resistance imparted by the first layer. The invention will be further described in reference to the following drawings where:

FIGURE 1 is a top plan view and fragmentary sectional views of the back surface of a typical coated tufted scatter rug of this invention;

FIGURE 2 is a fragmentary sectional view along lines 22 showing the one layer continuous first coating with the second coating on the first coating and on the raised portion of the back stitches; and

FIGURE 3 is a fragmentary sectional view of another embodiment showing a first coating between the back stitches and a second coating bonded directly to the raised portion of the back stitches.

The first coating composition is a latex composition which comprises an aqueous dispersion of a reinforcing resin or preferably a natural or synthetic elastomer or combinations thereof together with a high amount of filler such as clay and whiting, e.g. from about 100500 parts of filler per 100 parts (p.p.h.) of resin. The preferred elastomers or resins are those vulcanized hydrocarbon elastomers capable of being cured to provide suitable stiffness and abrasion resistance to the fabric with those elastomers containing more than 50 mole percent of ethylenical unsaturation i.e. capable of substantial cross linkage to promote stiffness, of particular utility. The preferred elastomer is a copolymer of from about 20 to 50 weight percent of a vinyl aromatic such as styrene, or an alkyl styrene like dimethyl styrene with from 50 to 80 weight percent of a diene such as a conjugated multiolefin like butadiene, isoprene, cyclopentadiene and the like. The commercial preferred elastomer is a latex containing 70/30 to 80/20 copolymer of butadiene and styrene which may be modified with minor amounts of 530 parts of a high styrene content butadiene copolymer. The first coating may also include natural rubber latices highly loaded with filler or combinations thereof with the the high styrene stiffening resins such as parts or more with a 100 parts of natural rubber latex. Other latices such as polyvinyl acetate, acrylic resins, and carboxylat ed elastomers may also be used. The second coating composition comprises a relatively high amount of an elastomer such as natural rubber which has a coeificient when dried and cured of about 0.8 or preferably 1.0 or more before dyeing or laundering and commonly has a relatively soft elastic resilient, rubbery, non-tacky surface when dried. This coating composition preferably is a latex composition containing natural or synthetic elastomers alone or with substantially lower quantities of inert fillers than the first composition such as from 10 to 150 p.p.h. Suitable elastomers or resins for the second coating include, but are not limited to, those natural and synthetic latices containing elastomers such as: butyl rubber which comprises a copolymer of from 80 to 99.9 weight percent of a C C isoolefin like isobutylene with from 0.1 to weight percent of a C -C multi-olefin such as a conjugated like butadiene and isoprene; halogenated butyl rubber such as chlorinated and brominated butyl rubber; nitrile rubbers like acrylonitrile-diene copolymers such as low content acrylonitrile-butadiene copolymer; polydienes such polybutadiene and polyi-soprene; halogenated polydienes such as polychloroprene, low vinyl aromatic-diene copolymers such as styrene-butadiene copolymers, polyurethanes, and other elastomers and combinations. Those elastomers which exhibit excellent antiskid properties and coefiicient of friction of above 1.0 before dyeing such as from 1.0 to 2.5 e.g. 1.2 to 1.7 when dried and after dyeing are preferred.

The second coating composition may include the addition of minor amounts of a hydrocarbon extender oil to further soften and enhance the non-skid values of the vulcanized blend. For example with 100 parts of a 75/25 butadiene-styrene copolymer from 525 parts of a naphthenic process oil may be added to give an oil extended SBR latex and to promote anti-skid characteristics of the cured blend. The anti-skid values of these elastomers may also be promoted by the incorporation of minor amounts of natural and synthetic plasticizer oils or esters such as dioctyl sebacate, dioctyl phthalate, and the like. Further the second coat may be obtained from organic solvent solution where necessary or desired, although at present the inexpensive latices compositions are preferred. Furthermore the second coating can be a foamed elastomer composition having high anti-skid value. For example the second coating may be a foamed SBR or natural rubber latex composition. In this embodiment the second coating can be applied as a froth or foam and cured in place or applied with suitable chemical blowing agents such as diazo compounds wherein there is an in situ generation of nitrogen, carbon dioxide or other inert gas to create a resilient foamed surface, or the blowing gas may be supplied from external sources such as air, and the like followed by curing of the foam. The character, type thickness, and density of the foam latex coating depends upon the desired end use of the material, but with carpet backing material is generally from to /2 inch thick and has a density of from 4 to 10 pounds per cubic foot.

Both the first and second latex compositions are partially or preferably fully cured in the presence of vulcanizing amounts of conventional curing agent of 120 p.p.h. of the elastomer. Suitable curing agents include, but are not limited to, metal oxides such as zinc oxide, elemental sulfur, quinones, amines, etc. with or without acceleration agent such as thiocarbamic acid derivatives like metal dialkyl thiocarbamates such as tellurium and zinc dimethyl and diethyl thiocarbamate. Optional ingredients include, but are not limited to, stabilizers, antioxidants, dyes and pigments, gums, thickeners, dispersing agents, detergents, anti-foam agents and the like. Curing depending upon the time, temperature and curing agents is normally accom lished in from 1-30 minutes e.g. 5-15 minutes at temperatures of from 250450 F.

The first coating layer often comprises from 10 to 30 Weight percent of vulcanized SBR latex with or without high styrene reinforcing resin, while the second coating layer often comprises over 40 preferably 50 to weight percent of an elastomer suitably vulcanized or cross linked either in solid film or foam form.

The filler dispersed or employed in these compositions can be inert fillers and clays of discrete particle size such as diatomaceous earths, kaolin, whiting, chalk, carbonates, pigments, metal oxides, carbon black, alumina, inorganic or organic fiber like asbestos fibers, glass fibers, cellulosic and synthetic textile fibers, wood flour, sawdust and paper.

The latex compositions may also optionally include other ingredients such as other elastomers, resins and plastics such as vinyl polymer like polyvinyl chlorides, polyvinyl acetates, polystyrene, polyolefins like polyethylene and polypropylene, waxes, natural resins and gums, phenol-aldehyde resins, polyacrylates, polyamides and the like to improve the properties or impart other desirable characteristics. These materials may be added in latex form or suitably dispersed in the latex compositions where necessary.

Turning now to the drawings, FIGURE 1 shows a top plan view of a coated, tufted scatter rug 10 having a plurality of longitudinal protruding tuft fiber back stitches 12a, 1) and c in a series of substantially uniform parallel rows, the stitches having an upper curved portion 13a, [2 and c protruding above the plane of the back surface. The heavy open mesh woven textile backing canvas-type fabric 14 of the rug has interstitial areas 16a, b and c between the raised row of the back stitches. The rug has a first continuous thick coating layer 20 and a second discontinuous coating layer 22 on the top of the stitches.

FIGURE 2 is a sectional view of the tufted carpet 10 of FIGURE 1 showing the continuous relatively thick first solid coating layer 20 comprising a reinforcing resin or elastomer with a high filler content over the entire back surface, i.e. the interstitial areas and the back stitches. A second discontinuous relatively thin solid coating layer 22 comprising a high elastomer content is located in the first coating and on the upper raised or floor contact portions 13 of the protruding back stitches.

FIGURE 3 is a sectional view of the tufted carpet 10 showing a continuous relatively thick continuous first solid coating layer 20 and a second discontinuous relaatively thin solid coating layer 22 directly bonded to the upper surface of the back stitches.

EXAMPLE I A cotton tufted carpet having the cotton tufts stitched in a series of uniform parallel rows through the backing fabric of the carpet and having a series of uniform and oz./sq. yd. is'commonly sufiicient to coat those round areas of the rug in contact with the floor. The rug was then oven dried at 325 F. for six minutes to dry and cure both coatings thereby bonding the second coat to parallel spaced protruding back stitches was roller coated the first coat produfmg a solid relatively flflck first with the following typical first coat formulation. layer and a relatively Second a If the second coat whether applied as a direct coat or dlSCOIl- ComPosltlon A: y Weight tinuous film can be colored to contrast with the first coat 3BR 2 i05 WP latex 75 100-00 thereby emphasizing its presence, or could also essen- Potasslum olgfite (Stabilizer) L00 tially match the precoat color as preferred. FRS174 (high Styrene latex) (85/15 Thus, as shown in the drawing in one preferred embodi- SBR) -00 ment only the top or raised protrusions of the back stitches Naiigawillifi (antioxidant) may be coated with the high rubber latex composition Zemte Special (accelerator) thereby promoting exceptionally high coeflicient of fric- Eihyl ZFnate ({lcceleratol') 100 15 tion of the rug at a minimal cost. In those special applica- Zmc Oxlde agent) 5-(30 tions where an exceptionally high adhesion strength is de- CWF f f clay (finer) 100-00 sired between the anti-skid second coating and the fabric, Wh1 tmg (filler) 200-00 or the bond strength between the reinforcing resin first 9 (Plrgment) 10-09 coating and the second coating is n0t wholly acceptable, Trisodium polyphosphate (dispe agent) 150 then prior to drying or curing or during the drying and Antffoam curing steps essentially all or a major part of the first com- Sodmm polyacry'late (thickener) position can, if necessary, be removed from the raised Karaya gum (th1ckener exterior formations. This may be accomplished by an Sulfur (separate) (mung agent) air knife, doctor blade or other means and these areas Thi l t composition was dj d to about 63 67 5 then coated only with the second anti-skid latex composiweight percent total solids content, (3400-6000 cps. visiioii- This application is pa y desirable Where cosity, Brookfield spindle #3 at 12 r.p.m.), and roll saturation of the raised back stitching fibers with the lower coated onto the back surface of tufted scatter rug fabric ViSCOSiiY rubbery Second Composition Such as a CaTbOXYicontaining raised fibrous formations to provide a smooth flied eiasmmei' is desiredsurface coating f f 10 to 20 12 to 16 Ounces f 30 It has been found that a coefficient of friction of 0.8 or d i h Square d f mg over h entire b k more offers good skid proof performance of scatter rugs surface area. This coating composition was partially 011 yp varnished hard Wood floorsdried in an oven for three minutes at 325 F. to a solid ylz Coefficients of friction Obtained y Coating 1111- tack-free coating layer that would not transfer from the dyed tuft cotton scatter rugs with the second coat being back fabric to rollers of subsequent handling. placed over the first coat and substantially on the top of The second elastomer coating composition was then apparallel row stitches in accordance with the teachings of plied essentially to all of the upper portions of the raised the present invention were as follows:

Table I Cocflicient of friction Amount Amount First coat (dry), Second coat (D),

oz/sq. yd o7/sq. yd Before After dyeing dyeing High filler SBR 14 Low filler None 0. 475 0. 550

fiil'gIgiSllI-lOD Do 14 do 0.6 0.825 1.400 Do 14 do 1.0 0. 875 1. 100

formations or protruding back stitches. This second coating composition had a typical formulation as follows.

Trisodium polyphosphate (dispersing agent) 0.50 Sodium polyacrylate (thickener) 0.5 Sulfur (separate) (curing agent) 2.50

The composition was adjusted to 65 weight percent total solids at a viscosity of 5001500 cps. applied to the previously coated back surface of the carpet by means of a metered transfer roller coater so that the top portions of the back protruding stitches were contacted and coated. A coating weight of 0.3 to 2.5 for example 0.5 to 1.5

The above data demonstrates that a lightly loaded elastomer latex composition or elastomer latex compositions alone or in combination with minor amounts of other elastomers for example 5 to 25 weight percent of other elastomers when employed as the second coat yield coefficients of friction of more than 0.8 after being dried and cured and before dyeing or laundry processing and more than 1.2 after dyeing and approach or equal the skid characteristics of natural rubber foam backing. As demonstrated the first coating alone gave wholly unacceptable and dangerous coeificient skid levels.

In a separate test a tufted cotton scatter rug #4 together with an essentially identical rug #1 were coated at a weight of from 12 to 14 ounces per square yard (dry weight) with a conventional latex scatter rug first coating. The top portions of the back stitches of rug #1 were then coated at a weight of from 0.6 to 1.0 ounce per square yard (dry weight) with a second skid-resistant latex coating. Each of the rugs was then cut in half and half of each rug subjected to eighteen (18) wash and tumble dry cycles through standard home laundry equipment with the following results:

'7 Table II Coelliciont of friction cycles 13 cycles Rug #4 (single coated) 0. 43 0. 40 Ru #1 (double coated) 2. 30 2. 30

The conventionally coated rug #4 had a very low coefiicient of friction before and after laundering and would certainly be regarded as dangerous under foot. The laundered half of each rug was badly faded, but rug #1, both before and after laundering, exhibited excellent skid-resistance.

Although the drawings have been explained in reference to employing a solid first coating, it is within the contemplation of this invention that the tops of the back stitching be coated with foamed elastomers thereby creating a backing having suitable stiffening properties, but with high skid-resistant characteristics. The foamed elastomer such as a foam natural rubber latex composition is applied to the protruding stitches from a pan foam kiss roll applicator in contact with the raised portions to transfer the desired amount of foamed rubber thereto.

A satisfactory method for applying two coatings continuously to a single length of scatter rug greige goods is to pass the goods over a conventional roller coater where the first inexpensive composition would be applied. The rug is then passed through a drying oven to remove all or a part of the solvent or water and to form a tack-free coating surface; then through a second roller coater, where the more expensive non-skid type second composition is metered onto one kiss roll, and subsequently transferred to the protruding back stitches of the rug. The rug is then passed through the oven for final drying and curing.

As described, the present invention provides lightweight inexpensive launderable scatter rugs having an exceptionally high coefiicient of friction on the surface contact area in combination with other essential and desired qualities of weight, stiffness and bulk.

Thus having described my invention, I claim:

1. An inexpensive, light-weight, washable scatter rug of enhanced skid resistance comprising a backing fabric and a plurality of fibrous tufts secured to the fabric to provide a tufted face surface, the opposite and back surface of the backing fabric characterized by a plurality of individual raised fibrous stitches, substantially the entire back surface coated with a relatively thick layer of a first composition comprising a cured elastomer compounded with inert filler materials to provide a desired degree of weight and stiffness to the rug, said coating being of a thickness insufficient to fill the spaces between said raised fibrous stitches and thus leaving an uneven back surface, and a second coating applied to said back surface, said second coating being applied to overlie only and substantially all of said raised fibrous stitches, said second coating comprising a cured elastomer compounded to provide a coefficient of friction to the rug of least 0.8.

2. An inexpensive, light-weight, washable scatter rug of enhanced skid resistance comprising a woven backing fabric and a plurality of fibrous tufts secured through the fabric to provide a tufted face surface, the opposite and back surface of the backing fabric characterized by a plurality of individual raised fibrous stitches with substantially the entire back surface coated with from about to 20 ounces dry Weight per square yard of a first composition comprising a cured elastomer and from about 100 to 500 parts of an inert filler material per 100 parts of elastomer, said coating being of a thickness insufficient to fill the spaces between said raised fibrous stitches and thus leaving an uneven back surface, and a second coating applied to said back surface, said second coating being applied to overlie only and substantially all of said raised fibrous stitches with from about 0.3 to 2.5 ounces dry weight per square yard of a second composition comprising a cured elastomer and from about 10 to 150 parts of an inert filler material per parts of elastomer and compounded to provide skid-resistant properties to the scatter rug.

3. A method of coating an inexpensive, light-weight, washable tufted rug to provide weight and stiffness together with a high degree of skid resistance which rug comprises a backing fabric, a plurality of fibrous tufts secured to the backing fabric to provide a tufted face surface with the opposite and back surface of the backing fabric characterized by a plurality of individual raised fibrous back stitches which method comprises:

coating substantially the entire back surface of the rug with a relatively thick layer of a first composition comprising a curable elastomer and an inert filler material and compounded to provide the desired degree of weight and stiffness to the rug;

drying this layer to a tack-free coating, said coating being of a thickness insufficient to fill the spaces between said raised fibrous stitches and thus leaving an uneven back surface;

applying second coating to overlie only and substantially all of the raised fibrous stitches, said second coating being a relatively thin layer of a second composition comprising a curable elastomer and compounded to provide anti-skid properties to the raised stitches and to have a coeflicient of friction when cured and before laundering of at least 0.8; and

curing the first and second elastomers in the first and second coatings. 4. The method of claim 3 wherein the second coating is applied and directly bonded to the upper portions of the raised fibrous stitches.

5. A method of coating an inexpensive, light-weight, washable tufted scatter rug to provide weight and stiffness together with a high degree of skid resistance which rug comprises a woven backing fabric, a plurality of fibrous tufts secured to the backing fabric to provide a tufted face surface and a back surface having a plurality of individual raised fibrous back stitches projecting above the back surface, which method comprises:

coating substantially the entire back surface of the rug with a first latex composition comprising a curable elastomer and from about 100 to 500 parts of inert filler material per 100 parts of elastomer to produce a relatively thick coating comprising from about 10 to about 20 ounces dry weight per square yard of e; drying this coating, said coating being of a thickness insufiicient to fill the spaces between said raised fibrous stitches and thus leaving an uneven back surface to a tack-free coating;

applying a second coating to overlie only and substantially all of the raised fibrous back stitches, said second coating being a latex composition comprising a curable elastomer and from about 10 to parts of inert filler material per 100 parts of elastomer, the composition compounded to provide a rug having a coefficient of friction of at least 0.8 before laundering and comprising a weight of about 0.3 to about 2.5 ounces dry weight per square yard of rug; and

simultaneously curing the first and second latex composition coatings thereby producing a tufted scatter rug carpet of desired weight, stiffness and high-skid resistant properties.

References Cited by the Examiner UNITED STATES PATENTS 1,223,538 4/1917 Tulley 117-7 2,752,277 7/1954 Keen.

RICHARD D. NEVIUS, Primary Examiner.

75 A. H. ROSENSTEIN, Assistant Examiner. 

1. AN INEXPENSIVE, LIGHT-WEIGHT, WASHABLE SCATTER RUG OF ENHANCED SKID RESISTANCE COMPRISING A BACKING FABRIC AND A PLURALITY OF FIBROUS TUFTS SECURED TO THE FABRIC TO PROVIDE A TUFTED FACE SURFACE, THE OPPOSITE AND BACK SURFACE OF THE BACKING FABRIC CHARACTERIZED BY A PLURALITY OF INDIVIDUAL RAISED FIBROUS STITCHES, SUBSTANTIALLY THE ENTIRE BACK SURFACE COATED WITH A RELATIVELY THICK LAYER OF A FIST COMPOSITION COMPRISING A CURED ELASTOMER COMPOUNDED WITH INERT FILLER MATERIALS TO PROVIDE A DESIRED DEGREE OF WEIGHT AND STIFNESS TO THE RUG, SAID COATING BEING OF A THICKNESS INSUFFICIENT TO FILL THE SPACES BETWEEN SAID RAISED FIBROUS STITCHES AND THUS LEAVING AN UNEVEN BACK SURFACE, AND A SECOND COATING APPLIED TO SAID BACK SURFACE, SAID SECOND COATING BEING APPLIED TO OVEERLIE ONLY AND SUBSTANTIALLY ALL OF SAID RAISED FIBROUS STITCHES, SAID SECOND COATING COMPRISNG A CURED ELASTOMER COMPOUNDED TO PROVIED A COEFFICIENT OF FRICTION TOTHE RUG OF LEAST 0.8. 